wp-content/themes/twentyfourteen/inc/featured-content.php

   1 <?php
   2 /**
   3  * Twenty Fourteen Featured Content
   4  *
   5  * This module allows you to define a subset of posts to be displayed
   6  * in the theme's Featured Content area.
   7  *
   8  * For maximum compatibility with different methods of posting users
   9  * will designate a featured post tag to associate posts with. Since
  10  * this tag now has special meaning beyond that of a normal tags, users
  11  * will have the ability to hide it from the front-end of their site.
  12  */
  13 class Featured_Content {
  14
  15         /**
  16          * The maximum number of posts a Featured Content area can contain.
  17          *
  18          * We define a default value here but themes can override
  19          * this by defining a "max_posts" entry in the second parameter
  20          * passed in the call to add_theme_support( 'featured-content' ).
  21          *
  22          * @see Featured_Content::init()
  23          *
  24          * @since Twenty Fourteen 1.0
  25          *
  26          * @static
  27          * @access public
  28          * @var int
  29          */
  30         public static $max_posts = 15;
  31
  32         /**
  33          * Instantiate.
  34          *
  35          * All custom functionality will be hooked into the "init" action.
  36          *
  37          * @static
  38          * @access public
  39          * @since Twenty Fourteen 1.0
  40          */
  41         public static function setup() {
  42                 add_action( 'init', array( __CLASS__, 'init' ), 30 );
  43         }
  44
  45         /**
  46          * Conditionally hook into WordPress.
  47          *
  48          * Theme must declare that they support this module by adding
  49          * add_theme_support( 'featured-content' ); during after_setup_theme.
  50          *
  51          * If no theme support is found there is no need to hook into WordPress.
  52          * We'll just return early instead.
  53          *
  54          * @static
  55          * @access public
  56          * @since Twenty Fourteen 1.0
  57          */
  58         public static function init() {
  59                 $theme_support = get_theme_support( 'featured-content' );
  60
  61                 // Return early if theme does not support Featured Content.
  62                 if ( ! $theme_support ) {
  63                         return;
  64                 }
  65
  66                 /*
  67                  * An array of named arguments must be passed as the second parameter
  68                  * of add_theme_support().
  69                  */
  70                 if ( ! isset( $theme_support[0] ) ) {
  71                         return;
  72                 }
  73
  74                 // Return early if "featured_content_filter" has not been defined.
  75                 if ( ! isset( $theme_support[0]['featured_content_filter'] ) ) {
  76                         return;
  77                 }
  78
  79                 $filter = $theme_support[0]['featured_content_filter'];
  80
  81                 // Theme can override the number of max posts.
  82                 if ( isset( $theme_support[0]['max_posts'] ) ) {
  83                         self::$max_posts = absint( $theme_support[0]['max_posts'] );
  84                 }
  85
  86                 add_filter( $filter,                              array( __CLASS__, 'get_featured_posts' )    );
  87                 add_action( 'customize_register',                 array( __CLASS__, 'customize_register' ), 9 );
  88                 add_action( 'admin_init',                         array( __CLASS__, 'register_setting'   )    );
  89                 add_action( 'switch_theme',                       array( __CLASS__, 'delete_transient'   )    );
  90                 add_action( 'save_post',                          array( __CLASS__, 'delete_transient'   )    );
  91                 add_action( 'delete_post_tag',                    array( __CLASS__, 'delete_post_tag'    )    );
  92                 add_action( 'customize_controls_enqueue_scripts', array( __CLASS__, 'enqueue_scripts'    )    );
  93                 add_action( 'pre_get_posts',                      array( __CLASS__, 'pre_get_posts'      )    );
  94                 add_action( 'wp_loaded',                          array( __CLASS__, 'wp_loaded'          )    );
  95         }
  96
  97         /**
  98          * Hide "featured" tag from the front-end.
  99          *
 100          * Has to run on wp_loaded so that the preview filters of the customizer
 101          * have a chance to alter the value.
 102          *
 103          * @static
 104          * @access public
 105          * @since Twenty Fourteen 1.0
 106          */
 107         public static function wp_loaded() {
 108                 if ( self::get_setting( 'hide-tag' ) ) {
 109                         add_filter( 'get_terms',     array( __CLASS__, 'hide_featured_term'     ), 10, 3 );
 110                         add_filter( 'get_the_terms', array( __CLASS__, 'hide_the_featured_term' ), 10, 3 );
 111                 }
 112         }
 113
 114         /**
 115          * Get featured posts.
 116          *
 117          * @static
 118          * @access public
 119          * @since Twenty Fourteen 1.0
 120          *
 121          * @return array Array of featured posts.
 122          */
 123         public static function get_featured_posts() {
 124                 $post_ids = self::get_featured_post_ids();
 125
 126                 // No need to query if there is are no featured posts.
 127                 if ( empty( $post_ids ) ) {
 128                         return array();
 129                 }
 130
 131                 $featured_posts = get_posts( array(
 132                         'include'        => $post_ids,
 133                         'posts_per_page' => count( $post_ids ),
 134                 ) );
 135
 136                 return $featured_posts;
 137         }
 138
 139         /**
 140          * Get featured post IDs
 141          *
 142          * This function will return the an array containing the
 143          * post IDs of all featured posts.
 144          *
 145          * Sets the "featured_content_ids" transient.
 146          *
 147          * @static
 148          * @access public
 149          * @since Twenty Fourteen 1.0
 150          *
 151          * @return array Array of post IDs.
 152          */
 153         public static function get_featured_post_ids() {
 154                 // Get array of cached results if they exist.
 155                 $featured_ids = get_transient( 'featured_content_ids' );
 156
 157                 if ( false === $featured_ids ) {
 158                         $settings = self::get_setting();
 159                         $term     = get_term_by( 'name', $settings['tag-name'], 'post_tag' );
 160
 161                         if ( $term ) {
 162                                 // Query for featured posts.
 163                                 $featured_ids = get_posts( array(
 164                                         'fields'           => 'ids',
 165                                         'numberposts'      => self::$max_posts,
 166                                         'suppress_filters' => false,
 167                                         'tax_query'        => array(
 168                                                 array(
 169                                                         'field'    => 'term_id',
 170                                                         'taxonomy' => 'post_tag',
 171                                                         'terms'    => $term->term_id,
 172                                                 ),
 173                                         ),
 174                                 ) );
 175                         }
 176
 177                         // Get sticky posts if no Featured Content exists.
 178                         if ( ! $featured_ids ) {
 179                                 $featured_ids = self::get_sticky_posts();
 180                         }
 181
 182                         set_transient( 'featured_content_ids', $featured_ids );
 183                 }
 184
 185                 // Ensure correct format before return.
 186                 return array_map( 'absint', $featured_ids );
 187         }
 188
 189         /**
 190          * Return an array with IDs of posts maked as sticky.
 191          *
 192          * @static
 193          * @access public
 194          * @since Twenty Fourteen 1.0
 195          *
 196          * @return array Array of sticky posts.
 197          */
 198         public static function get_sticky_posts() {
 199                 return array_slice( get_option( 'sticky_posts', array() ), 0, self::$max_posts );
 200         }
 201
 202         /**
 203          * Delete featured content ids transient.
 204          *
 205          * Hooks in the "save_post" action.
 206          *
 207          * @see Featured_Content::validate_settings().
 208          *
 209          * @static
 210          * @access public
 211          * @since Twenty Fourteen 1.0
 212          */
 213         public static function delete_transient() {
 214                 delete_transient( 'featured_content_ids' );
 215         }
 216
 217         /**
 218          * Exclude featured posts from the home page blog query.
 219          *
 220          * Filter the home page posts, and remove any featured post ID's from it.
 221          * Hooked onto the 'pre_get_posts' action, this changes the parameters of
 222          * the query before it gets any posts.
 223          *
 224          * @static
 225          * @access public
 226          * @since Twenty Fourteen 1.0
 227          *
 228          * @param WP_Query $query WP_Query object.
 229          * @return WP_Query Possibly-modified WP_Query.
 230          */
 231         public static function pre_get_posts( $query ) {
 232
 233                 // Bail if not home or not main query.
 234                 if ( ! $query->is_home() || ! $query->is_main_query() ) {
 235                         return;
 236                 }
 237
 238                 $page_on_front = get_option( 'page_on_front' );
 239
 240                 // Bail if the blog page is not the front page.
 241                 if ( ! empty( $page_on_front ) ) {
 242                         return;
 243                 }
 244
 245                 $featured = self::get_featured_post_ids();
 246
 247                 // Bail if no featured posts.
 248                 if ( ! $featured ) {
 249                         return;
 250                 }
 251
 252                 // We need to respect post ids already in the blacklist.
 253                 $post__not_in = $query->get( 'post__not_in' );
 254
 255                 if ( ! empty( $post__not_in ) ) {
 256                         $featured = array_merge( (array) $post__not_in, $featured );
 257                         $featured = array_unique( $featured );
 258                 }
 259
 260                 $query->set( 'post__not_in', $featured );
 261         }
 262
 263         /**
 264          * Reset tag option when the saved tag is deleted.
 265          *
 266          * It's important to mention that the transient needs to be deleted,
 267          * too. While it may not be obvious by looking at the function alone,
 268          * the transient is deleted by Featured_Content::validate_settings().
 269          *
 270          * Hooks in the "delete_post_tag" action.
 271          *
 272          * @see Featured_Content::validate_settings().
 273          *
 274          * @static
 275          * @access public
 276          * @since Twenty Fourteen 1.0
 277          *
 278          * @param int $tag_id The term_id of the tag that has been deleted.
 279          */
 280         public static function delete_post_tag( $tag_id ) {
 281                 $settings = self::get_setting();
 282
 283                 if ( empty( $settings['tag-id'] ) || $tag_id != $settings['tag-id'] ) {
 284                         return;
 285                 }
 286
 287                 $settings['tag-id'] = 0;
 288                 $settings = self::validate_settings( $settings );
 289                 update_option( 'featured-content', $settings );
 290         }
 291
 292         /**
 293          * Hide featured tag from displaying when global terms are queried from the front-end.
 294          *
 295          * Hooks into the "get_terms" filter.
 296          *
 297          * @static
 298          * @access public
 299          * @since Twenty Fourteen 1.0
 300          *
 301          * @param array $terms      List of term objects. This is the return value of get_terms().
 302          * @param array $taxonomies An array of taxonomy slugs.
 303          * @return array A filtered array of terms.
 304          *
 305          * @uses Featured_Content::get_setting()
 306          */
 307         public static function hide_featured_term( $terms, $taxonomies, $args ) {
 308
 309                 // This filter is only appropriate on the front-end.
 310                 if ( is_admin() ) {
 311                         return $terms;
 312                 }
 313
 314                 // We only want to hide the featured tag.
 315                 if ( ! in_array( 'post_tag', $taxonomies ) ) {
 316                         return $terms;
 317                 }
 318
 319                 // Bail if no terms were returned.
 320                 if ( empty( $terms ) ) {
 321                         return $terms;
 322                 }
 323
 324                 // Bail if term objects are unavailable.
 325                 if ( 'all' != $args['fields'] ) {
 326                         return $terms;
 327                 }
 328
 329                 $settings = self::get_setting();
 330                 foreach( $terms as $order => $term ) {
 331                         if ( ( $settings['tag-id'] === $term->term_id || $settings['tag-name'] === $term->name ) && 'post_tag' === $term->taxonomy ) {
 332                                 unset( $terms[ $order ] );
 333                         }
 334                 }
 335
 336                 return $terms;
 337         }
 338
 339         /**
 340          * Hide featured tag from display when terms associated with a post object
 341          * are queried from the front-end.
 342          *
 343          * Hooks into the "get_the_terms" filter.
 344          *
 345          * @static
 346          * @access public
 347          * @since Twenty Fourteen 1.0
 348          *
 349          * @param array $terms    A list of term objects. This is the return value of get_the_terms().
 350          * @param int   $id       The ID field for the post object that terms are associated with.
 351          * @param array $taxonomy An array of taxonomy slugs.
 352          * @return array Filtered array of terms.
 353          *
 354          * @uses Featured_Content::get_setting()
 355          */
 356         public static function hide_the_featured_term( $terms, $id, $taxonomy ) {
 357
 358                 // This filter is only appropriate on the front-end.
 359                 if ( is_admin() ) {
 360                         return $terms;
 361                 }
 362
 363                 // Make sure we are in the correct taxonomy.
 364                 if ( 'post_tag' != $taxonomy ) {
 365                         return $terms;
 366                 }
 367
 368                 // No terms? Return early!
 369                 if ( empty( $terms ) ) {
 370                         return $terms;
 371                 }
 372
 373                 $settings = self::get_setting();
 374                 foreach( $terms as $order => $term ) {
 375                         if ( ( $settings['tag-id'] === $term->term_id || $settings['tag-name'] === $term->name ) && 'post_tag' === $term->taxonomy ) {
 376                                 unset( $terms[ $term->term_id ] );
 377                         }
 378                 }
 379
 380                 return $terms;
 381         }
 382
 383         /**
 384          * Register custom setting on the Settings -> Reading screen.
 385          *
 386          * @static
 387          * @access public
 388          * @since Twenty Fourteen 1.0
 389          */
 390         public static function register_setting() {
 391                 register_setting( 'featured-content', 'featured-content', array( __CLASS__, 'validate_settings' ) );
 392         }
 393
 394         /**
 395          * Add settings to the Customizer.
 396          *
 397          * @static
 398          * @access public
 399          * @since Twenty Fourteen 1.0
 400          *
 401          * @param WP_Customize_Manager $wp_customize Theme Customizer object.
 402          */
 403         public static function customize_register( $wp_customize ) {
 404                 $wp_customize->add_section( 'featured_content', array(
 405                         'title'          => __( 'Featured Content', 'twentyfourteen' ),
 406                         'description'    => sprintf( __( 'Use a <a href="%1$s">tag</a> to feature your posts. If no posts match the tag, <a href="%2$s">sticky posts</a> will be displayed instead.', 'twentyfourteen' ),
 407                                 esc_url( add_query_arg( 'tag', _x( 'featured', 'featured content default tag slug', 'twentyfourteen' ), admin_url( 'edit.php' ) ) ),
 408                                 admin_url( 'edit.php?show_sticky=1' )
 409                         ),
 410                         'priority'       => 130,
 411                         'theme_supports' => 'featured-content',
 412                 ) );
 413
 414                 // Add Featured Content settings.
 415                 $wp_customize->add_setting( 'featured-content[tag-name]', array(
 416                         'default'              => _x( 'featured', 'featured content default tag slug', 'twentyfourteen' ),
 417                         'type'                 => 'option',
 418                         'sanitize_js_callback' => array( __CLASS__, 'delete_transient' ),
 419                 ) );
 420                 $wp_customize->add_setting( 'featured-content[hide-tag]', array(
 421                         'default'              => true,
 422                         'type'                 => 'option',
 423                         'sanitize_js_callback' => array( __CLASS__, 'delete_transient' ),
 424                 ) );
 425
 426                 // Add Featured Content controls.
 427                 $wp_customize->add_control( 'featured-content[tag-name]', array(
 428                         'label'    => __( 'Tag Name', 'twentyfourteen' ),
 429                         'section'  => 'featured_content',
 430                         'priority' => 20,
 431                 ) );
 432                 $wp_customize->add_control( 'featured-content[hide-tag]', array(
 433                         'label'    => __( 'Don&rsquo;t display tag on front end.', 'twentyfourteen' ),
 434                         'section'  => 'featured_content',
 435                         'type'     => 'checkbox',
 436                         'priority' => 30,
 437                 ) );
 438         }
 439
 440         /**
 441          * Enqueue the tag suggestion script.
 442          *
 443          * @static
 444          * @access public
 445          * @since Twenty Fourteen 1.0
 446          */
 447         public static function enqueue_scripts() {
 448                 wp_enqueue_script( 'featured-content-suggest', get_template_directory_uri() . '/js/featured-content-admin.js', array( 'jquery', 'suggest' ), '20131022', true );
 449         }
 450
 451         /**
 452          * Get featured content settings.
 453          *
 454          * Get all settings recognized by this module. This function
 455          * will return all settings whether or not they have been stored
 456          * in the database yet. This ensures that all keys are available
 457          * at all times.
 458          *
 459          * In the event that you only require one setting, you may pass
 460          * its name as the first parameter to the function and only that
 461          * value will be returned.
 462          *
 463          * @static
 464          * @access public
 465          * @since Twenty Fourteen 1.0
 466          *
 467          * @param string $key The key of a recognized setting.
 468          * @return mixed Array of all settings by default. A single value if passed as first parameter.
 469          */
 470         public static function get_setting( $key = 'all' ) {
 471                 $saved = (array) get_option( 'featured-content' );
 472
 473                 $defaults = array(
 474                         'hide-tag' => 1,
 475                         'tag-id'   => 0,
 476                         'tag-name' => _x( 'featured', 'featured content default tag slug', 'twentyfourteen' ),
 477                 );
 478
 479                 $options = wp_parse_args( $saved, $defaults );
 480                 $options = array_intersect_key( $options, $defaults );
 481
 482                 if ( 'all' != $key ) {
 483                         return isset( $options[ $key ] ) ? $options[ $key ] : false;
 484                 }
 485
 486                 return $options;
 487         }
 488
 489         /**
 490          * Validate featured content settings.
 491          *
 492          * Make sure that all user supplied content is in an expected
 493          * format before saving to the database. This function will also
 494          * delete the transient set in Featured_Content::get_featured_content().
 495          *
 496          * @static
 497          * @access public
 498          * @since Twenty Fourteen 1.0
 499          *
 500          * @param array $input Array of settings input.
 501          * @return array Validated settings output.
 502          */
 503         public static function validate_settings( $input ) {
 504                 $output = array();
 505
 506                 if ( empty( $input['tag-name'] ) ) {
 507                         $output['tag-id'] = 0;
 508                 } else {
 509                         $term = get_term_by( 'name', $input['tag-name'], 'post_tag' );
 510
 511                         if ( $term ) {
 512                                 $output['tag-id'] = $term->term_id;
 513                         } else {
 514                                 $new_tag = wp_create_tag( $input['tag-name'] );
 515
 516                                 if ( ! is_wp_error( $new_tag ) && isset( $new_tag['term_id'] ) ) {
 517                                         $output['tag-id'] = $new_tag['term_id'];
 518                                 }
 519                         }
 520
 521                         $output['tag-name'] = $input['tag-name'];
 522                 }
 523
 524                 $output['hide-tag'] = isset( $input['hide-tag'] ) && $input['hide-tag'] ? 1 : 0;
 525
 526                 // Delete the featured post ids transient.
 527                 self::delete_transient();
 528
 529                 return $output;
 530         }
 531 } // Featured_Content
 532
 533 Featured_Content::setup();